Which of the following statements about gastrinoma (Zollinger-Ellison syndrome) is/are correct?

A. As many as 75% of gastrinoma patients have sporadic disease; 25% have gastrinoma associated with multiple endocrine neoplasia type 1 (MEN 1).

B. Extrapancreatic gastrinomas are common, and exploration should include careful assessment of the duodenum and peripancreatic lymph nodes.

C. Diarrhea may be a prominent presenting feature of some patients with gastrinoma. 

D. Before elective operation acid-reducing medications such as omeprazole should be administered.

DISCUSSION: Gastrinoma patients typically present with peptic ulceration of the upper gastrointestinal tract and abdominal pain. As many as 50% of patients may have diarrhea, which may be a prominent feature in some cases. Approximately 25% of gastrinoma patients have the disease associated with the MEN-1 syndrome, whereas 75% have a sporadic variety of the disease. Recent evidence indicates that extrapancreatic gastrinomas are common. Careful attention must be paid to the duodenum and peripancreatic lymph nodes at the time of abdominal exploration. Before elective operation it is imperative that the gastric acid hypersecretion be controlled. The control of gastric hypersecretion is best performed by the administration of one of the substituted benzimidazoles, such as omeprazole or lansoprazole.